Raymond Zielinski

 

Professor of Plant Biology
249 Morrill Halll MC-116
(217) 333-6785

Education

B.S., Biology, Lehigh University
Ph.D., 1979, Rutgers University
Postdoc, University of Maryland

Teaching

IB202, Structure and Function
IB472, Plant Molecular Biology

Research Overview

The broad objective of my laboratory is to understand how higher plantstransduce second messenger Ca2+ signals to produce the appropriate physiological response to a specific stimulus. Current efforts are focused on understanding the organization, and patterns and regulation of expression of genes encoding calmodulin in Arabidopsis thaliana. By cDNA and genomic cloning, we have shown that a family of at least ten genes encodes calmodulin in Arabidopsis. Each gene has a slightly different pattern of expression at the whole organ level. We are currently asking whether the genes are differentially expressed at the level of cell-type by using the promoters of the genes to drive the expression of GUS and GFP reporter genes, in transgenic tobacco and Arabidopsis plants. We found that the ten calmodulin genes in Arabidopsis encode eight isoforms of the protein, which may be unique to calmodulins in higher plants. To determine whether there are significant differences among calmodulin isoforms, we are taking both biochemical and genetic approaches. In the genetic approach, we are testing the abilities of the isoforms to functionally complement a yeast calmodulin null. In the biochemical approach, we have constructed E. coli strains engineered to overexpress cloned calmodulin cDNAs. We are comparing the abilities of these recombinant proteins to activate calmodulin-regulated enzymes in vitro, to bind Ca2+, and to bind protein and model peptide substrates.

 

A second project is aimed at examining the interaction of calmodulin with its target proteins in vivo. We have constructed and expressed green fluorescent protein- (GFP) and blue fluorescent protein- (BFP) calmodulin gene fusions in yeast, which functionally complement a yeast calmodulin null strain. To assay for calmodulin-target protein interaction in vivo, we are co-transforming this yeast strain with BFP-putative target protein gene fusions and testing for fluorescence resonance energy transfer (FRET) between the BFP-calmodulin and GFP-target protein partners. We are particularly interested in applying this system to test the physiological relevance of calmodulin interaction with transcription factors.

Recent Publications

Ali R, Zielinski RE, Zangerl AR, Crofts AR, Berenbaum MA and DeLucia EH (2006) Expression of plant cyclic nucleotide gated cation channels in yeast.  Journal of Experimental Botany 57: 125-138.

 

Tang JY, Zielinski RE, Zangerl AR, Crofts AR, Berenbaum MA and DeLucia EH  (2006) The differential effects of herbivory by first and fourth instars of Trichoplusia ni (Lepidoptera: Noctuidae) on photosynthesis in Arabidopsis thaliana.  Journal of Experimental Botany 57: 527-536.

 

Hua, B.-G., Mercier, R. W., Zielinski, R. E., and Berkowitz, G. A. (2003).  Functional interaction of calmodulin with a plant cyclic nucleotide gated cation channel. Plant Physiol. Bioche m. 41, 945-954

 

Nelissen, H., Clarke, J. H., DeBlock, M., DeBlock, S., Vanderhaeghen, R., Zielinski, R. E., Dyer, T., Lust, S., Inze, D., and Van Lijsebettens, M. (2003) DRL1, a homologue of the yeast KTI12/TOT4 protein, has a function in meristem activity and organ growth in plants. Plant Cell 15, 639-654.